XML 75 R83.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Preferred Stocks (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Class of Stock [Line Items] |  |  |
Preferred stock redemption price upon liquidation (in dollars per share) | $ 100 |  |
Preferred stocks | $ 15,000 | $ 15,000 |
Cumulative Preferred Stock, Par Value $100 Issuable in Series [Member] |  |  |
Class of Stock [Line Items] |  |  |
Authorized preferred cumulative shares (in shares) | 500,000 | 500,000 |
Cumulative preferred shares, par value (in dollars per share) | $ 100.00 | $ 100.00 |
Preferred stock, series 4.50% [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred stock redemption price at the option of the company (in dollars per share) | $ 105 |  |
Preferred stocks | 10,000 | 10,000 |
Preferred shares outstanding (in shares) | 100,000 | 100,000 |
Preferred stock, $100 par value | 4.50% | 4.50% | 4.50%
Preferred stock, dividends per share, declared | $ 4.50 | $ 4.50 | $ 4.50
Preferred stock, series 4.70% [Member] |  |  |
Class of Stock [Line Items] |  |  |
Preferred stock redemption price at the option of the company (in dollars per share) | $ 102 |  |
Preferred stocks | $ 5,000 | $ 5,000 |
Preferred shares outstanding (in shares) | 50,000 | 50,000 |
Preferred stock, $100 par value | 4.70% | 4.70% | 4.70%
Preferred stock, dividends per share, declared | $ 4.70 | $ 4.70 | $ 4.70
Cumulative preferred stock A, without par value, issuable in series [Member] |  |  |
Class of Stock [Line Items] |  |  |
Authorized preferred cumulative shares (in shares) | 1,000,000 | 1,000,000 |
Cumulative preference stock , without par value, issuable in series [Member] |  |  |
Class of Stock [Line Items] |  |  |
Authorized preferred cumulative shares (in shares) | 500,000 | 500,000 |

X
- Definition The redemption price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends may be redeemed at the option of the company with certain limitation + References No definition available. + Details
Name: | mdu_PreferredStockRedemptionPriceOptionOfCompany
Namespace Prefix: | mdu_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer. + References No definition available. + Details
Name: | mdu_PreferredStockRedemptionPricePerShareUponLiquidation
Namespace Prefix: | mdu_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate dividends declared during the period for each share of preferred stock outstanding. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate par or stated value of issued nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable preferred shares, par value and other disclosure concepts are in another section within stockholders' equity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.28) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29 -Article 5 + Details
Name: | us-gaap_PreferredStockValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant